1997 Volume 66 Issue 2 Pages 259-267
The root system of rice nursling seedlings is composed of a seminal root and crown roots from coleoptilar node. The roots were cut at various locations, and the treated seedlings were grown for seven days after transplanting to clarify the role of the crown roots in the rooting and development. Even when the roots were cut at 1.5 cm from the base of the root, growth of the seedlings was similar to that of the control. However, growth was significantly reduced when cut at a length of 0.5 cm from the base. The growth of transplanted seedlings, including the emergence rate of the third leaf, was barely influenced by excision of the root tips of a seminal root and four crown roots, but growth was severely reduced by cutting at the bases of a seminal root and the longest crown root. The growth of the transplanted seedlings decreased in accordance with the total root length remaining after the treatments. These results indicate that the rooting and development of transplanted nursling seedlings are reduced according to the total length of the root remaining after treatment. It is conjectured that the crown roots from the coleoptilar node play a large role in the absorption of water and nutrients just after transplanting, and promote the rooting and development of transplanted nursling seedlings through emergence of the first nodal roots.
